matthews



(No Model.)

B. S. MATTHEWS. SAFETY DEVICE-FOR ELEVATORS.

Patented June 7, 189:2.

Inventor Witnesses: W W 6%. WWW

[n W. Sm, Attorney UNITED STATES PATENT FFICE.

EDWIN. S. MATTHEXVS, OF CINCINNATI, OHIO, ASSIGNOR OF ONE-HALF TO JAMES L. HAVEN, OF SAME PLACE.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 476,289, dated June 7, 1892. Application filed January 25, 1892. fierial No. 419,146. (No model.)

To all whom it may concern.-

vented certain new and useful Improvements in Elevator Safety Devices, of lowing is a specification.

v This invention pertains to improvements in devices for preventing the descent of the car of an elevator in case of accidental damage to the parts which sustain the car.

My invention will be readily understood from the following description, taken in connection with the accompanying drawings, in which- Figure 1 is a front elevation of an elevatorcar provided with mechanism exemplifying my invention, a portion of the head-beam being broken away to expose mechanism beyond the broken-away portion; Fig. 2, a side elevation of the same with the governor parts omitted, so as to expose parts that would otherwise be hidden by them, a portion of one of the guide-rails appearing in vertical section; and Fig. 8, an enlarged perspective view of a portion of the base of the car, viewed as if the car were turned upon its side, this view illustrating the construction of the lower jaws.

In the drawings, A indicates the usual headbeam of the elevator-car; B, the usual cardeck; 0, the usual stiles of the car; D, the usual tension-straps tying the head-beam to the deck; E, the jaws attached to the headbeam and adapted to engage the usual vertical guide-rails; F, the lower jaws to similarly engage the guide-rails and secured to the deck of the car, the straps engaging the upper and lower jaws and thus bonding the entire general structure; G, a portion of one of the usual guide-rails; 1-1, a shaft extending across the car and journaled at its ends in the two lower jaws F,this shaft being disposed somewhat to the rear of the guide-rails, so that the ends of which the folthe shaft may extend as far as the outer por-.

tions of the jaws; J, a segmental recess formed in the outer portion of each lower jaw concentric with the shaft H, this recess opening forwardly to the guide-rail and also downwardly to the base of the jaws; K, the bearings in the jaws for the shaft H, concentric with the recesses J; L, a recess in each lower jaw extending from the shaft-bearing K downwardly the full extent of the jaw-castings; M, a block removably secured in each of the recesses L and serving when in place to prevent the displacement of the shaft from its bearings K; N, a pawl, one firmly secured to each end of shaft H with its heel seated in and fitting the recess J, the end of the pawl presenting itself downwardly near but free from the guide-rail; O, the hoisting-ropes arranged in pairs, of which pairs there may be any desired number, Fig. 2 showing two pairs of these ropes, each pair of ropes being formed in the exemplification of a continuous rope bent under a sheave in the head-beam; P, the sheavej ust referred to, this sheave constituting,iu effect, an evener for the two hoisting-ropes of the pair, whereby the strain upon the two ropes of the pair is equalized; Q, collars firmly secured upon the hoisting-ropes in such position that all of them will be normally upon about the same level; R, a spindle mounted in the head-beam; S,a lever mounted on this spindle and projecting to the side of the car contiguous to aguide-rail; T, a pawl-rod connected at its upper end to the le ver S and pivoted at its lower end to apawl N, thelower end of the rod, where it pivotallyengages the pawl, being slotted, so that the pawl may have a slight degree of upward movement independent of the pawl-rod; U,alever rigidly connected with lever S; V, a counterbalance-rope, of which there may be any desired number, coming down to the head-beam from above and bending under a sheave mounted on the head beam and then attached to the lever U, so that the strain on the counterbalance-rope tends to lift the pawl-rod5 W, the sheave last mentioned; X, a toggle with one extremity pivoted to lever U and with its other extremity pivoted to a fixed point on the head-beam, the intermediate pivot of this toggle being somewhat above a line cutting the two end pivots; Y, a trigger-lever pivoted to the head-beam and hooking over the intermediate pivot of the toggle and preventing the further upward flexing of the toggle; Z, a lever connected with trigger-lever Y, so that the two levers oscillate together; ct, the usual governor; b, the vertical spindle of the governor engaging the lever Z in such manner that that movement; of the spindle resulting from increase of speed of rotation of the governor will nnhook trigger-lever Y from the toggle; c, a plate disposed overand near to the collars Q, this plate being provided with suitable openings, so that the plate may clear the hoisting-ropes; d, a stem attached to this plate and engaging the lever Z, so that if the plate rises the trigger-lever Y will be disengaged from the toggle and permit the toggle to rise, and e a strained spring tendingto lift the pawl-rod and pull the pawls into action.

Normally the pawls N are free from the guide-rails; but if the pawl-rod T be pulled up the ends of the pawls will bite into the guide-rail and lock the car and prevent its further descent. The two pawls being fast on shaft H, the lifting of one pawl by the pawl-rod will at the same time lift the other pawl, and the slot in the lower end of the pawl-rod permits of the pawls rising independent of the pawl-rod after they have once taken a bite in the guide-rails. After the initial biting of the pawls or either of them, if one should engage more decidedly than the other, the rising of the pawls is of course antoinatican action due to the weight of the car and the slot in the pawl-rods permits this independent rise of the pawls.

The lower jaw-castings F, firmly secured to the car-deck, straddle their guide-rails, and when the pawls go into action the tendency is of course to shear off the ends of shaft II where the pawls are attached. This tendency is guarded against in the present case by causing the heels of the'pawls to seat in the recess J, whereby the shaft is relieved entirely from all strain except the slight torsional strain of lifting into initial action the pawl farthest from the one to which pawlrod '1 is attached. The walls of the recesses J not only engage the outer portions of the heels of the pawlsthose portions farthest from the guide-rails-but they reach inwardly under the pawls toward the guide-rails, whereby when a pawl reaches a horizontal position and is under the heaviest strain this inwardly-projecting portion of the recess-wall prevents shearing descent of the outer end or heel of the pawl, which would otherwisetake place, the pawl tending to act as a powerful lever, with the central upper portion of the wall as a fulcrum. Recess L in the jaw-castings permits the downward removal of the shaft, with both pawls attached, without a general dismantling of the base of the car, it being only necessary to remove the blocks M. The bearings K for shaft H are disposed well up in the jaw-castings, and the removable blocks M become mere keepers to retain the shaft, and they take none of the strains when the pawls go into action. This is due to the fact that the recesses L and blocks M are located forward of the axial plane of the shaft.

It will be noticed that the strain on counterbalance-rope V tends to pull the pawls into action and that this-tendency is resisted by the toggle, and that the release of the toggle is prevented by trigger Y. It will also be noticed that spring e also tends to pull the pawls into action and that the toggle also resists this tendency. If all the hoisting-ropes should break, the car would start to descend at abnormal speed and the governor, by virtue of such speed, would trip the trigger and thereby, in an obvious manner, permit the counterbalance-rope orsprin g, or both, to pull the pawls into action and arrest the further descent of the car. A safeguard is thus formed against danger in case of the breakage of all of the hoisting-ropes; but all the hoisting-ropes of an elevator are not apt to break at one time,'and provision is made for arresting the descent of the car in case any one of the hoisting-ropes breaks.

-If any one of the hoisting-ropes 0 shouldbreak, the other rope of its pair, being relieved of the equalizing-strain of the rope which was broken, will move upwardly and its collar Q will lift plate 0 and thereby, in an obvious manner, trip the trigger and allow the coun-- terbalance-rope to pull the pawlsinto action. It will therefore be seen that the breakage of any one hoisting-rope will result in instantly locking the car, and that the breaking of all of the hoisting-ropes will result in looking the car as soon as it shall have started downwardly at abnormal speed.

If all the ropes attached to the car should break, then the trigger would be disengaged and the spring would throw the pawls into action; but while this spring 6 thus furnishes an independent agency for throwing the pawls into action when the spring is allowed to act it is also a useful agent in connection with the counterbalance-rope. The counterbalance of an elevator varies in its effect at different positions of the car. With a light car and a very high lift there is a material change in the effect of the counterbalance-weight as the car goes to the bottom of the elevator-- well, the length of counterbalance-rope ining to compensate for the weight of the weight itself, the pull of the counterbalance-weight on the car thus lessening as the car moves toward the bottom of the well. Therefore it will be seen that the spring, while capable of setting the pawls in the absence of the employment of a counterbalance-rope for this purpose, is of great utility in aiding the counterbalance-rope when employed in setting the pawls into action.

When the trigger is released, the toggle moves upwardly and presents itself above the head-beam of the car. In this position it can readily be reached by the foot of a man standing on the head-beam, and downward pressure on the toggle will reset the safety device to normal position, the toggle furnishing a powerful means for resetting the safety device.

I claim as my invention- 1. In an elevator safety device, the combi- IIO nation, substantially as set forth, with an elevator-car and mechanism connected therewith for lifting a pawl-rod in case of emergency, of castings at the two sides of the car provided with bearings for a pawl-shaft and with se mental recesses concentric thereto having wall portions projecting inwardly in contact with the under portion of the heel of the pawl, a shaft journaled in said bearings and projecting into said recesses, and a pawl fast upon each end of said shaft and seating with their heels in said recesses and over said inwardlyprojecting floors and adapted to engage the guide-rails of the car, and a pawl-rod connecting said shaft and said pawl-rod-lifting mecl1- anism.

2. In an elevator safety device, the combination, substantially as set forth, with an elevator-car and mechanism thereon to turn a shaft in case of emergency, of a shaft having a pawl at each end and connected with said shaft-turning mechanism, and a casting secured to each side of the car and provided with a rigid bearing opposing the strain of the shaft downwardly and away from the can guide and with a recess opening inwardly and downwardly and provided also with an inwardly and downwardly open pawl-heel bearing exterior to said shaft-bearing, and a removable block secured within each of said castings at the recess leading from said shaftbearing and preventing the inward displacement of the shaft.

3. In an elevator safety device, the combination, substantially as set forth, with an elevator-car, a locking device thereon to engage the guide-rails of the elevator when drawn into action, a straining means, connections on the car from said straining means to said locking device to pull the locking device into action, an obstruction, as a toggle, to normally meet the strain and prevent the transmission of the strain to the locking device, a trigger arranged to hold said obstruction normally in obstructing position, one or more pairs of hoisting-ropes connected with the car, an evener to equalize the strain upon each hoisting-rope of a pair, collars upon the hoistingropes, a plate near said collars and arranged to be moved thereby as the hoisting-ropes shift with reference to the car, and connections between said plate and trigger Whereby the movement of said plate effects the release of said trigger/ 4. In an elevator safety device, the combination, substantially as set forth, of an elevator-car, a locking device, a straining means arranged to draw the locking device into action, a trigger arranged to prevent the action of the locking device, one or more hoistingropes attached to the car and arranged in pairs and provided with collars, and connections adapted to cause the shifting of said collars to release said trigger.

5. In an elevator safety device, the combination, substantially as set forth, of an elevator-car, a locking device thereon, a straining means arranged to pull said locking device into action, one or more hoisting-ropes arranged in pairs and provided with collars, a governor, a trigger to prevent the action of the locking device, and connections from said trigger to said governor and said collars, whereby the shifting of the collars or abnormal speed of the governor effects the release of the trigger.

6. In an elevator safety device, the combination, substantially as set forth, of an elevator-car, a locking device thereon, a counterbalancerope arranged to pull said locking device into action, a spring arranged to pull said locking device into action, a trigger arranged to prevent the action of the locking device, and a governor arranged to trip the trigger if the car travels at abnormal speed.

7. In an elevator safety device, the combination, substantially as set forth, of an elevator-car, a locking device thereon, and counterbalance-rope arranged to pull said locking device into action, a spring arranged to pull said locking device into action, one or more hoisting-ropes arranged in pairs and provided With' collars, a trigger to prevent the action of the locking device, and connections from said trigger to said collars, Whereby the shifting of the collars effects the release of the trigger.

8. In an elevator safety device, the combination, substantially as set forth, of an elevator-car, a locking device thereon, a straining means arranged to draw said locking device into action, a trigger to prevent the action of the locking device, mechanism to effect the release of said trigger in emergencies, and a toggle abutting at one end upon a fixed point on said car and connected at its other end with the locking device so asto flex when the locking device goes into action and-serve, when pressed back to normal position, to restore the locking device to normal idle condition.

EDWIN S. MATTHEWS.

W'itnesses:

JAS. FITTON, J. W. Sun. 

